A Mechanistic Study of Hydroboration of 1-Octene with 1,3,2-Dithiaborolane and 1,3,2-Dithiaborinane. Part 1. Synthesis and Kinetic Studies

Alkylthioboranes 1,3,2-dithiaborolane and 1,3,2-dithiaborinane have been synthesized from the reaction of BH3·SMe2 with 1,2-ethanedithiol and 1,3-propanedithiol, respectively. These heterocyclic boranes disproportionated significantly during their synthesis. The rate constants, and the enthalpies and entropies of the hydroboration reaction of 1-octene with 1,3,2-dithiaborolane and 1,3,2-dithiaborinane have been investigated, and we have shown that hydroboration with these boranes is slow and proceeds via an associative mechanism.Keywords: Hydroboration, disproportionation, boranes, transition statesPDF and Supplementry file attache

3D X-Ray Nanotomography of Cells Grown on Electrospun Scaffolds

Here, it is demonstrated that X-ray nanotomography with Zernike phase contrast can be used for 3D imaging of cells grown on electrospun polymer scaffolds. The scaffold fibers and cells are simultaneously imaged, enabling the influence of scaffold architecture on cell location and morphology to be studied. The high resolution enables subcellular details to be revealed. The X-ray imaging conditions were optimized to reduce scan times, making it feasible to scan multiple regions of interest in relatively large samples. An image processing procedure is presented which enables scaffold characteristics and cell location to be quantified. The procedure is demonstrated by comparing the ingrowth of cells after culture for 3 and 6 days

A Mechanistic Study of Hydroboration of 1-Octene with 1,3,2-Dithiaborolane and 1,3,2-Dithiaborinane. Part 2. A DFT Study of Disproportionation and Hydroboration

The hydroboration reactions of propene with 1,3,2-dithiaborolane and 1,3,2-dithiaborinane in their ground states have been studied using density functional theory (DFT) at the B3LYP/3-21+G and B3LYP/6-31+G(d) levels. Hydroboration and disproportionation transition states have been determined and activation energies for these transition states were compared. It has been shown that hydroboration reactions require slightly higher activation energies than disproportionation, and yield thermodynamically more stable products.Keywords: Hydroboration, disproportionation, DFT, transition states, potential energy surfacePDF and Supplementry file attache

Synthesis of Oxo- and Thio-analogues of 2-Oxo-2H-chromen-7-yl Dimethylcarbamates

Arange of novel 2-oxo-2H-chromen-7-yl dimethylcarbamates was synthesized containing either an oxygen or sulphur atom in the α-position to the carbonyl or thiocarbonyl group of the amide moiety. The synthesis and spectroscopic data of these compounds are reported. Microwave synthesis was essential for the successful synthesis of some of the sulphur-containing carbamates. The synthesized compounds will be used in a subsequent study on the influence of the α-substituent on the amide rotational barrier.Keywords: rotational barrier, thiocarbamate

Part II: Ab Initio and NMR Investigations into the Barrier to Internal Rotation of various Oxo- and Thio- Analogues of 2-Oxo-2H-chromen-7-yl Dimethylcarbamates

A range of 2-oxo-2H-chromen-7-yl dimethylcarbamates were synthesized as described in part I of this publication, containing either an oxygen or sulphur α to the carbonyl or thiocarbonyl group of the amide moiety. Variable temperature and exchange spectroscopy NMR was performed on these compounds and the barrier to free amide rotation was calculated. Each of these compounds were also modelled ab initio and the gas phase barrier to rotation calculated. These three sets of data were compared and the influence of the α-heteroatom on rotation for amides and thioamides evaluated.Keywords: Thiocarbonyl, amide, rotational barrie

The holistic phase model of early adult crisis

The objective of the current study was to explore the structural, temporal and experiential manifestations of crisis episodes in early adulthood, using a holistic-systemic theoretical framework. Based on an analysis of 50 interviews with individuals about a crisis episode between the ages of 25 and 35, a holistic model was developed. The model comprises four phases: (1) Locked-in, (2) Separation/Time-out, (3) Exploration and (4) Rebuilding, which in turn have characteristic features at four levels—person-in-environment, identity, motivation and affect-cognition. A crisis starts out with a commitment at work or home that has been made but is no longer desired, and this is followed by an emotionally volatile period of change as that commitment is terminated. The positive trajectory of crisis involves movement through an exploratory period towards active rebuilding of a new commitment, but ‘fast-forward’ and ‘relapse’ loops can interrupt Phases 3 and 4 and make a positive resolution of the episode less likely. The model shows conceptual links with life stage theories of emerging adulthood and early adulthood, and it extends current understandings of the transitional developmental challenges that young adults encounter

Applying the balanced scorecard to local public health performance measurement: deliberations and decisions

<p>Abstract</p> <p>Background</p> <p>All aspects of the heath care sector are being asked to account for their performance. This poses unique challenges for local public health units with their traditional focus on population health and their emphasis on disease prevention, health promotion and protection. Reliance on measures of health status provides an imprecise and partial picture of the performance of a health unit. In 2004 the provincial Institute for Clinical Evaluative Sciences based in Ontario, Canada introduced a public-health specific balanced scorecard framework. We present the conceptual deliberations and decisions undertaken by a health unit while adopting the framework.</p> <p>Discussion</p> <p>Posing, pondering and answering key questions assisted in applying the framework and developing indicators. Questions such as: Who should be involved in developing performance indicators? What level of performance should be measured? Who is the primary intended audience? Where and how do we begin? What types of indicators should populate the health status and determinants quadrant? What types of indicators should populate the resources and services quadrant? What type of indicators should populate the community engagement quadrant? What types of indicators should populate the integration and responsiveness quadrants? Should we try to link the quadrants? What comparators do we use? How do we move from a baseline report card to a continuous quality improvement management tool?</p> <p>Summary</p> <p>An inclusive, participatory process was chosen for defining and creating indicators to populate the four quadrants. Examples of indicators that populate the four quadrants of the scorecard are presented and key decisions are highlighted that facilitated the process.</p